The field of the present invention is pulleys for timing belts for engines and particularly the construction thereof.
Heretofore timing belt pulleys generally have been constructed from a single piece or multiple pieces including a machined or cast outer wheel. The wheel must necessarily be constructed to provide some means for maintaining the indexing of the timing belt or chain. Consequently, the outer wheel must include some mechanism such as teeth to insure proper indexing. Additionally, with the advent of modern timing belts, a variety of belt tooth designs have been available. Such designs have necessitated intricate pulley surface designs as well. Additionally, the belts generally require pulleys of wider axial dimension to reduce the pressure on the belt.
The foregoing conditions and requirements have often necessitated rigorous machining or finishing operations to form the pulley surface. In the high production environment of automobile manufacturing and the like, such intricate designs and the like have proven to be a major expense. Accordingly, an inexpensive, accurate and durable timing belt pulley wheel has long been sought.